The Internet plays a growing role in the economy. This paper extrapolates this trend and analyses a world where most transactions take place in "cyberspace". We ask the following question: how does the design of the search engine affect the incentives to innovate and the economy’s long run...

This paper analyzes the implications of advertising for firm dynamics and economic growth through its interaction with R&D investment at the firm level. We develop a model of endogenous growth with firm heterogeneity that incorporates advertising decisions. We calibrate the model to match...